Fuse plug



March 17, 1925. 1,530,319

H. T. PAlSTE FUSE PLUG Filed Oct. 27, 1922 Patented Mar. 17, 1925.

UNITED STATES PATENT OFFICE.

HENRY T. PAISTE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO H. T.ZPAISTE COMPANY, OF PHILADELPHIA, VANIA.

PENNSYLVANIA, A CORPORATION OF PENNSYL- FUSE PLUG.

Application filed October 27, 1822,

To all whom it may concern:

Be it known that I, HENRY T. PAISTE, a citizen of the United States,residing in Philadelphia, Pennsylvania, have invented a Fuse Plug, ofwhich the following is a specification.

One object of this invention is to provide a fuse plug of the typeincluding a renewable fuse-carrying capsule, which shall be simple andsubstantial in construction and which shall insure good electricalcontact between the fuse on the capsule and the terminal shell on theplug body.

another object of my invention is to pro vide a fuse plug of the abovetype including a body of insulating material of novel form particularlyadapting it to be con veniently held and turned when it is desired toscrew the plug into or out of a receptacle.

I also desire to provide'a capsule carrying a relatively fusible linkand especially designed for use in a fuse plug of the above noted type,the invention including a novel construction for holding in place theotherwise free end of the fusible element so that this will not springoutwardly from the capsule and become bent or broken.

It is further desired to provide a fuse plug body with novel means forremovably holding therein a capsule carrying a fuse or fusible link. i

In the drawings herewith:

Figs. 1 and 2 are respectively a side elevation and a plan of the fuseplug constituting my invention;

Figs. 3 and 4: are respectively a side elevation and an inverted plan ofthe fuse plug capsule;

Figs. 5 and 6 are respectively a plan and an inverted plan of the fuseplug body with the capsule removed;

Fig. 7 is a longitudinal vertical section on the line 7-7, Fig. 5; and

Fig. 8 is a longitudinal vertical section of the fuse capsule takenthrough the fusible link.

In the above drawings, 1 represents an elongated, substantiallycylindrical casing of insulating material such as porcelain, having oneend closed and formed with a cavity 3, which while for the most part ofcircular cross section, has a portion 4 ad- Serial No. 597,328.

jacent its open end of polygonal section, in the present case hexagonal.The external cylindrical surface of the casing 1 has longitudinalgrooves 5 extending from one end to the other, each communicating withradially extending grooves 6 formed in the open end of the casing, whichlatter grooves open into the cavity of said casing.

Mounted on the open end of the casing 1 is a threaded sheet metal shell7 formed to screw into a standard lamp socket or receptacle and havingone edge notched or forced into certain of the longitudinal grooves 5,as indicated at 8. Those grooves into which said shell is extended areformed with shoulders 5) against which the portions 8 of the shell abutto prevent it being drawn off the end of the casing. Said shell '7 isinwardly flanged as indicated at 10 so as to extend over the otherwiseopen end of the casing 1 and is thereafter cut to form a series ofangular tongues 11 which are bent into the portion 4-. of the cavity tolie immediately adjacent the flat walls thereof. These tongues howeverdo not. lie immediately in contact or parallel with said walls butextend toward each other so as to form more or less yielding contactmembers for engagement with a fusible link on the fuse capsule. Theradial passages 6 in the end of the casing permit of the escape of gasesfrom the cavity 3 into the longitudinal groove 5, since the tongues 11are spaced away from and make a more or less loose fit with the walls ofthe casing.

The fuse capsule consists of a morc or less tapering body including aportion 12 of circular section and a portion 13 of hexagonal sectionformed with an integral head or flange 14. This structure is made ofporcelain and the body 1213 is formed with a cavity 15 opening into itsunfianged end. A strip of relatively fusible metal 16 has one end inelectrical engagement with a metal terminal 17 in the form of a piece ofsheet material having a branched bod extending into the flange 14v. andincluding two oppositely projecting semi-circular portions lying againstthe otherwise flat outer face of said flange adjacent the centerthereof.

One end of the fusible strip 16 extends between the branches of thisterminal menu her and is formed in two tongues bent at right angles inopposite directions so as to lie parallel and: in engagement; with. thesemi-circular portions of said terminal 17.

From the latter the link extends centrallythrough the flange into thecavity 15, of the fuse; body, then outwardly through a notch in the edgeof the open end thereof and back in engagement with the external;surface of said body to the under side of the flange. Here it is offsetas indicated at 18-, beingfbent into a recess of said flange so as to beeffectually held. in place and then extended radiallyfout. over' theunder surface ofthe flange.

The body 12-1'3 is of such dimensions as to be capable ofenteringthecavity 4 -3 of the casingl, the flat sides of-the portion 13 beingformed tocooperate with the spring tongues 11, which frictionally engageit to removably hold. the capsule in thecasing after it has beeninserted. When in this position, the portion ofthe fusiblelink extendingover the externalsurface of' the body 12 -13 is electrically engaged"with one of, the tongues 11 and when the capsule is forcibly pressedinto engagement with the turned'in portion lO of thelshell 7, the latterengages the outwardly projecting part 16 of'the link. i

The casing with its parts and the capsule therefor constitute a fuseplug which may be screwed into a receptacle of suitable construction,whereupon the oppositely. projecting ends l6 -of the fusible link areens gaged with one terminal ofsaidsreceptacle, from which the circuit iscompleted through the fusible link to one of the spring tongues 11,thence to the threaded shell"? andto the second terminal of thereceptacle.

In the event ofan abnormally heavy current flow through the fusible link16, this is fused in the ordinary manner and, as abovefnoted', any,gases formed or resulting from this fusing, pass out between the tongues11' and'the wallsofthe cavity 3, thence into the passages 6 and'to thegrooves 5, through whiehthfey are-led so as to eS-, cape-into theair.

By reason-of the; polygonal cross section of=the portion-4 of the casing11 and of the openingin the shell 7, the similarly formed portion 13ofthecapsule body-is prevented from rotating,- after being inserted. AsaI consequence when the plug is rotated by a turning force applied to itscasing 1, the capsule,is likewise turned; and niay, be withdrawn withthebody from the receptacle in which the plug is used.

I.- claim-:

1. The: combination in a fuse, plug of a threaded shell inwardly fiangedat: one end and having spring tongues projecting inwardly from the inneredge of said flanged end; anelongatecb hollow casing of insulatingmaterial having an open end fitting into said threaded shell; andhaving-itszopposite end integral with its bodyqand' closed; there beinggrooves extending longitudinally in the outer surface of saidcasingandipassages in the edge of the open end thereof; coniinunicating with.its hollow, interior, with a capsule having a portionforined to passthrough the opening in the flange of the threaded shell into the casing,and including a link electrically engaging one off the spring tongues,one end of the link terminating atone end of the capsule,

i. The-combination in a fuse plug of; an elongated substantiallycylindricalbodyof insulating material integrally; closed at one end andhavinglongitudinally extending grooves inits external surface;radial'pas' sages in the edge of the open enduof said casing; a threadedmetallic shell fixedion the casing including a flange extending-inwardlyover theedge of the open end thereof and having spring tonguesprojectinginwardly into the cavity'of'thecasingy with a fuse'capsulecomprising a body havinga flange atone end formed with a recess in itsunder side, a fusible link extending from the outer faceof said" flangethrough the body, then longitudinally overthe; external surfacethereofinto the recessin theunder side of the flange.

8-. A; fuse plug capsule. including abodyportion having anexternalflange; aternlinal plate on theouterface; and'a-fuse link,having one end engaging said terminal plate, extendingtherefrom throughthe body portion of the capsule to the-outside thereof, thencelongitudinally -overthe external surface of'the capsule and'in-toa-recess in the flange, and then radially outward overthe under surfaceof the flange;

HENRY T PAISTE;

